When reading a paper like this, I always like to ask myself, what are the basic assumptions that underlie the methodology involved? What contentions are simply stated as fact or generated in a computer model, rather than demonstrated with real, physical evidence? I will confess here that I don’t believe computer models really prove anything. Sure, they can suggest many things and point out areas of interest, but I live the real world and prefer real physical evidence upon which to base important conclusions. That doesn’t mean I discount models out of hand—it simply means that I look for physical evidence to confirm or deny what the models are saying. So I asked myself a series of questions about the basic issues in this paper. Here are some of the questions that I came up with (the answers follow).

1. Can the Antarctic ice cores be dated with sufficient accuracy to establish a firm temperature chronology?

2. Are the 80 temperature proxies used in the paper sufficiently accurate to establish a solid global temperature chronology?

3. Can CO2 in the ice cores be measured with validity and accuracy?

4. Can the difference in the age of the trapped air and the age of the enclosing ice be determined and is it constant with age?

5. Are CO2 measurements from air bubbles valid or do diffusion and the uncertainty in the timing of isolation of air in bubbles render them invalid?

6. Is the data from Antarctic ice cores consistent with data from the Greenland ice cores?

7. Is the temperature chronology of the ice cores and global proxies consistent with the well-dated, global glacial record?

8. Is the so-called ‘see-saw’ of climate changes between hemispheres valid, i.e, are climate changes in the Northern Hemisphere out of phase with those in the Southern Hemisphere?

10. Since CO2 is incapable of causing climatic warming by itself (CO2 makes up only 0.038% of the atmosphere and accounts for only a few percent of the greenhouse gas effect), is there evidence of concomitant increase in water vapor (which causes more than 90% of the greenhouse gas effect)?

11. Is the AMOC the only viable causal mechanism? What about the influence of the Pacific Ocean, which covers about half the Earth’s surface

So, what is the main contention of this paper and what does it imply? The authors claim to have “compelling evidence that rising CO2 caused much of the global warming” at the end of the last ice age, roughly 11,000 to 25,000 years ago. According to the authors, “if you reconstruct temperatures on a global scale – and not just examine Antarctic temperatures – it becomes apparent that the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age.” The crux of their contention is illustrated in their Figure 2.

Shakun et al. Figure 2. The Red line is Antarctic temperature curve based on ice cores; the yellow dots are CO2 measurements from ice cores; the blue line is composite global temperature from 80 proxies.

Willis has sliced and diced the data behind these curves so be sure to read his analyses. I’ll refer to some of his graphs and conclusions but look at the Shakun et al. contentions from a somewhat different angle. Because this is such a marked divergence from the widely held view that CO2 lagged rising temperatures at the end of the last ice age, careful scrutiny must be given to evidence and assumptions upon which this contention is based. Right off the bat, a most surprising conclusion in this paper is that the authors claim that correlation proves cause. Simply showing that CO2 correlates with anything surely doesn’t prove that CO2 was the cause. It’s the same kind of mindset involved with the oft-heard claim that if we have had global warming while CO2 was rising that proves the cause was the rise in CO2. Heck, I had hair before CO2 began to rise, but I don’t blame that on CO2.

So let’s look at each of questions posed above.

How accurate is the dating of Antarctic ice cores? How can you date ice that has nothing in it that can be directly dated? The Shakun et al. paper states that they use the methodology of Lemieux-Dudon et al. (2010), which involves construction of a model using estimates of snow accumulation rates, temperature, firn densification rates, and ice flow rates, all of which vary from glacier to glacier and from glaciation to interglaciation (thus introducing large potential errors). The modeling data is then modified by matching with tephra horizons, sulfate spikes, δ18O, firn densification model results, and orbital tuning. All of the assumptions built into the modeling are cumulative, resulting in large possible age errors. As Lemieux-Dudon point out “One special feature of glaciological models is alarge model error due to unresolved physics and errors on the forcing fields, clearly affecting the quality of the inferred dating scenarios.” What this means of course is that the age determinations of the Antarctic cores are, at best, educated guesses with large uncertainties. Because chronology is so critical to the Shakun et al. contention, the ages of the Antarctic cores shown in their Figure 2 cannot be considered accurate.

Are the 80 temperature proxies used in the paper sufficiently accurate to establish a solid global temperature chronology? Willis Eschenbach has made a detailed analysis of the data used to construct the global temperature curve in Figure 2 of Shakun et al.(see this in his web posting) He plotted individual curves for each of the 80 temperature proxies used to create Figure 2 in the Shakun et al. paper. What he found was large variability in the data, which led him to conclude that “The variety in the shapes of these graphs is quite surprising Yes, they’re all vaguely alike, but that’s about all. The main curiosity about these, other than the wide variety of amounts of warming, is the different timing of the warming.” When he ploted all the individual proxies all together (see below), the scatter is readily apparent, leading him to conclude: “It’s clear that there is warming since the last ice age.” “But if you want to make the claim that CO2 precedes the warming? I fear that this set of proxies is perfectly useless for that. How on earth could you claim anything about the timing of the warming from this group of proxies? It’s all over the map.”

===============================================================

Dr. Easterbrook requested this correction below saying:

As one of your readers pointed out, Willis used ‘Year’ for his time scale (meaning years BC, rather than years BP). I didn’t notice this (geologists always use years BP for events older than a few thousand years), so there really isn’t a discrepancy between the Shakun global curve and Willis’s data points. That graph and the text with it should be replaced with the attached file “dje response to Nature paper x.doc”) or it can just be removed from the posted version. That also means that the YD shown vertical time lines in the previous graph needs to be moved over 2000 yrs so we might as well just Willis’s graph (see attached file).

Sorry for the glitch–my fault–I should have caught it, but the thought never occurred to me that Willis would use 25,000 years BC. It doesn’t change any other of the other material.

Large scatter of individual data points on Willis’s plot from the 80 proxies used in the construction of the Shakun et al. temperature curve. I’ve added lines to show the age of Younger Dryas interval, which doesn’t correspond to the dip in the Shakun et al. temperature data.

Just for fun, I superimposed the curves on Shakun et al. figure 2 over Willis’s data point plot (see below). Because the global temperature curve (the blue curve) was presumably derived from the data in Willis’s plot, it should fit well with it. Interestingly, it doesn’t. I’ve shown with a blue arrow the dip in temperature that corresponds to the Younger Dryas and a black arrow pointing to what should be the same dip in temperature on the plot of individual data points. Other arrows point to similar differences for the end of the Younger Dryas. Now you would think that since the Shakun et al. blue curve was constructed from the individual data points shown on the graph, the two should surely be compatible! I’ve also shown on the graph the well-established age of the Younger Dryas—note that the Shakun et al. global temperature data points show a dip in temperature (presumably the Younger Dryas) that is considerably younger. Makes you wonder!

==============================================================

3. Can CO2 in the ice cores be measured with validity and accuracy?

4. Can the difference in the age of the trapped air and the age of the enclosing ice be determined and is it constant with age?

5. Are CO2 measurements from air bubbles valid or do diffusion and the uncertainty in the timing of isolation of air in bubbles render them invalid?

Because these questions are all inter-related let’s consider them together. The validity of measurement of CO2 from bubbles in ice cores has been challenged in a number of studies. There are several basic problems: (1) air becomes trapped in ice during the conversion of snow to firn to ice. Air in the snow/firn phase remains in contact with surface air until it turns to ice and seals off air bubbles from further mixing with surface air. The depth at which sealing occurs varies considerably, depending on the rate of firn densification, and may extend to more than 100 meters and take a thousand years or more. This means that the age of air in a bubble is not the same as the age of the inclosing ice. Snow densification rates vary considerably between temperate and polar glaciers and between glacial and interglacial climates, making it difficult to measure and date adequately. In any case, rates are not likely to be constant. (2) a second problem results from possible diffusion along the walls of an air bubble, which can upset the CO2 concentration in the bubble. These and other problems mean that measurement of CO2 in ice cores is not straight forward—measurement of CO2 concentrations in ice bubbles and determination of the age of the air are likely to be quite variable. General trends are apparent in CO2 ice core measurements, but variability in CO2 concentrations and age remains problematic.

At this point, answering the remaining questions is quite obviously going to take some time, so they will be considered in Part 2, coming soon.

Some decades ago, my geophysical colleagues developed a model of how a concealed discrete body of magnetic rock would disturb the normal flux pattern of the Earth’s magnetic field. This started in the days when calculations were done on a mechanical machine with a handle that you pulled to perform a preset calculation. The hard work was completed in the years before the PC sat on so many desks.
By marking out a surveyed grid (with altitudes) and using a sensitive magnetometer, the natural field was mapped, usually at an area where airborne survey showed a discrete anomaly. Then, hypothetical bodies were fitted, usually with an ellipsoidal shape, but with length and direction of X,Y and Z axes variable, as well as the angles between them. There was usualy a need to drill for a sample to get an idea of remanent magnetism so that work could be done on the induced magnetism perturbations. After modelling several hundred discrete bodies near Tennant Creek, Northern Territory, the geophysicists became uneeringly good at predicting the position and disposition of the body, whose top could be 300 meters below land surface.Thus, about 5 new gold/copper/bismuth mines were found, some of them quite valuable, but invisible to other surface exploration methods. The originators were mainly Mr L.A. Richardson and C.B. Kirkpatrick.
This is mentioned in the context of the sentences above, “I will confess here that I don’t believe computer models really prove anything. Sure, they can suggest many things and point out areas of interest, but I live the real world and prefer real physical evidence upon which to base important conclusions.”
My words here are give hope that models can go fairly close to a ‘proof’ if perturbing variables are understood well enough to be eliminated or compenstated.
As an aside, one can philosophise that a reason for success was the need for each geophysicist to work with the data manually, over and over, to get a personal ‘feel’ for it. There are dangers in the closed, black box approach that seems to get more emphasis these days than getting hands dirty from actual data.

It has been shown recently that CO2 diffuses through ice (Scripps Oceanographic Institute). It follows Fick’s Second Law of Diffusion. Very slowly, but we are talking kiloyears here. It diffuses from areas of high concentration to low concentration. SO high concentration bubbles will diffuse toward the outside, to be in equilibrium ONLY when the concentration in the bubble is equal to concentration outside. Well-known physics. Nothing can be really trapped! It is properly said, then, that the situation is metastable. Even mylar balloons lose helium in a short while, and mylar is very impermeable, relatively speaking.

Every gas diffuses through every solid. Even isotopes become concentrated in the heavier isotope, even though the difference is an atomic weight or two.

ALSO, when the ice core is removed from “down under”, where there exists high pressure at the bottom of the ice column, the pressure is removed, and the ice bubbles, retaining the pressure from below, diffuse faster toward lower pressure at the surface. Diffusion then becomes directly proportionally increased in accordance with the pressure gradient. This is additive to the diffusion gradient.

Conclusion: Unless one instantaneously tests the bubbles, AND goes back in time to when the bubbles were deposited, one can never know the original concentration.

Of course, if one could go back in time, why not just test the air? Measure temperature while we are at it?

The difference between the timing of the YD and temperature proxies’ drop makes me nervous; this isn’t just a bookkeeping error confusing BP and BC dating, is it? Don’t laugh; engineers can even confuse km and mi. when setting Mars Probe rocket decel timings ….

The proxies themselves often take time to respond and adjust to environmental changes, and these responses vary greatly between different proxies and between different locations, therefore it is not valid to use globally averaged proxies to determine timing relationships beyond a certain error margin.

A basic example would be sea level, it takes time to melt ice at a certain temperature, so therefore any measurement of palaeo-sea level would be offset from the period of warmth with which it is related, as the ice that would melt from such warmth would take a certain period of time to then effect the sea level (and then effect other proxies such as corals, and so on). You can also get negative and flatline responses once certain point is reached (e.g with tree rings and warmth), as well as feedback effects which can also increase the level of response. These sort of things vary greatly between proxies, and therefore any strong conclusions from averaged analyses of past proxies must be treated with utmost caution; in particalar conclusions regarding timing relationships and magnitude.

Academics know this, its just that they sometimes forget, to get a paper or to try and make a point.

But the same goes for the whole AGW thing, my main problem with it is that I think they have got the general response rates of the earth wrong, for much the same reasons as illustrated above. The earth will warm much more slowly than their models suggest (think hundreds to thousands of years, not decades).

…
As an aside, one can philosophise that a reason for success was the need for each geophysicist to work with the data manually, over and over, to get a personal ‘feel’ for it. There are dangers in the closed, black box approach that seems to get more emphasis these days than getting hands dirty from actual data.

More importantly your colleagues ground-truthed the model by boring at the anomally locations.

Don Easterbrook asks “Can the difference in the age of the trapped air and the age of the enclosing ice be determined and is it constant with age?” He notes that “the age of air in a bubble is not the same as the age of the inclosing ice.”

The study by Caillon et al. (2003) says “One way to circumvent this difficulty is to use records of atmospheric CO2 content and temperature contained only in the trapped gases.”

This graph http://www.friendsofscience.org/assets/documents/FOS%20Essay/CaillonTermIII%203.jpg
from the paper Caillon et al. (2003) finds that the CO2 increase lagged Antarctic deglacial warming by 800 years. The authors measured the isotopic composition of argon40 and CO2 concentration in air bubbles in the Vostok core during the end of the third most recent ice age (Termination III), 240,000 years before the present. The graph shows CO2 and Argon40 isotope, with the time scale shifted by 800 years to present the best fit overlay. Both the CO2 and the Argon40 are gases extracted from the same air bubble in the ice core. The Argon40 is not in the surrounding ice. There can be no time lag between these two measurements. Deuterium in the ice is often used to measure the ice temperature. The Argon40 has a R2 correlation factor with deuterium of 0.85, indicating that Argon40 is an excellent temperature proxy of the trapped air. The temperature is not recorded when the snow falls, but both temperature and CO2 are recorded at some later time when there is no longer exchange with the atmosphere.

In a comment response to one of his articles, Willis indicated that he used a BC/AD timeline vs the BP timeline used by Shakun. Did you account for that or does that ~2000y difference explain your YD offset. Terry

An avalanche search dog can sniff human scent through several feet of snow. If scent (gases related to bacteria on epithelials) can percolate through the snow in minutes, I’d expect CO2 would move through snow also. As snow is compressed, air is expelled to the surface, leaving only a relatively small example of the air remaining between the ice crystals. But that remaining air should represent a very similar relative composition of the various gases. However, if CO2 diffuses through ice (as mentioned previously), precise dating and quantifying the relative concentration at any given time would be very fuzzy indeed.

A couple of points. The proof that C02 causes warming is not from corelation. Its from experiemental evidence and basic engineering.

The question is how much warming.

The paper argues this.
1. The INITIAL cause of the warming was a change in orbital parameters. THEN
2. Excess warmth in NH. Then
3. ICE melting and a fresh water pulse THEN
4. A warming in the SH, leading to
5. MORE c02 outgassed from the ocean.
C02 both leads ( enhances) and lags ( as a feedback) the temperature rise.
It doesnt really change our view of things but adds in a few more details about the sequence.

No study of paleo climate change change the physics of c02 causing warming. It does. how MUCH is the key question.

To that end. The IPCC argues that the mean number for climate sensitivity is 3C . Whats that mean. That mean if we have 3.7Watts of addditional forcing ( from the sun or C02 ) we will see 3C of temperature rise. And further, doubling C02 from 280 to 560 will cause 3.7W of forcing.

Is sensitivity 3C as Hansen and the IPCC claim?
This study by Shakun implies a LOWER number actually. It implies 2.5C

“What he found was large variability in the data, which led him to conclude that”, “The variety in the shapes of these graphs is quite surprising Yes, they’re all vaguely alike, but that’s about all. The main curiosity about these, other than the wide variety of amounts of warming, is the different timing of the warming.”[…] “It’s clear that there is warming since the last ice age.” “But if you want to make the claim that CO2 precedes the warming? I fear that this set of proxies is perfectly useless for that. How on earth could you claim anything about the timing of the warming from this group of proxies? It’s all over the map.”

Willis is simply negating the fact the Northern Hemisphere warmed slower than the Southern Hemisphere, when you read the paper and not take Willis word on the subject, you can clearly see that there are many different warming start dates for the proxy’s http://i44.tinypic.com/34gncox.jpg the paper is getting a “global” temperature record. Is it not obvious that around the world during a major climatic shift with large areas of ice receding and forest growing over thousands of years, you are going to get a mix of proxy temperature records!! Each proxy record is a peer reviewed study which is referenced in the paper. If you have a problem with one of them, by all means read!!

“Comparison of the Shakun et al. global temperature curve with the data from which it was constructed. The blue arrows point to the Younger Dryas dip in temperatures and the black arrows point to the ending of the Younger Dryas. The two should match, but don’t.”

This point amazed me, the paper is a global record of temperatures, and the Younger Dryas dip was only really seen in the Northern Hemisphere. It is all explained in the paper and I have already shown the graph which explains it, http://i44.tinypic.com/34gncox.jpg What is even more bizarre is how you show this on a graph that is not averaged and by the look of it are only considering the yellow dots on the graph??

http://www.ncdc.noaa.gov/paleo/abrupt/data4.html
As others have noted there is an error in position of YD is the second graph here. Similarly in the overlay , please correct this. Labeling an axis “year” is insufficient if you do not specify whether it’s AD or BP, though the range of the data makes it obvious.

The YD provides an important check on the timings which, despite the error here, still don’t line up. Though it is a lot nearer than it appears here this would seem to be a key factor in determining any lag between the two. Perhaps posting the Shakun graph itself would be helpful (fair usage) since the paper is pay-walled.

I don’t understand what is interesting about this study. Carbon dating at the 15,000 year level isn’t accurate enough for what they are trying to do. The accuracy decreases by 2 to the power of the number of half lives (5,730 years). Given that 1/2 a half life is +/- half a century the error at 3 half-lives is on the order of time (a millennium) that you are trying to measure. Also ice core dating errors and the proxy dating errors are independent and affected by different factors.

They have dated parts of the same animal (from frozen tundra) as 15,000 and 21,000 years old. We don’t know which end of the tree they are dating.

They would have a dating accuracy of better than 1% to make this study useful.

This doesn’t even touch the issues that the proxies for temperature would have to be reasonably accurate and respond to temperature and not moisture and other variables.

The ice cores at least have the advantage that the CO2 and temperature signals are related to the same relative layers even though they may be skewed or modulated.

PS the offset shown here looks like >=2500 years so there will be something like a 500y offset when dates are corrected. This is just about what Shakun needed to revert the previous work showing CO2 lagged temps.

As ever totally unrealistic uncertainty estimates enable drawing a conclusion that is no way justified by the data.

Mashing 80 very different proxies from all around the globe and showing the minimalistic error bars is complete fiction. This is from the same school of post-impressionist science as Mann’s hockey stick. I’m not impressed.

Distant past is almost imponderable.
More recent past is controversial, the hockey stick and like.
One thing is almost a certainty
– CO2 atmospheric content can’t affect changes in the Earth’s magnetic field
– global temperature change can’t affect changes in the Earth’s magnetic field
regardless of which one came first
Not so certain is that the sun’s magnetic oscillations can’t affect changes in the Earth’s magnetic field.
– If the changes in the Earth’s magnetic field for the last 350 years plotted against hockey stick result: no correlation
– If the changes in the Earth’s magnetic field for the last 350 years plotted against the Loehle’s temperature ‘non tree ring’ reconstructions result: good correlation.http://www.vukcevic.talktalk.net/LLa.htm
It is to the ones who earn leaving from the CO2 hypothesis, to make sure that their profession is safeguarded by maintaining the ‘science is settled’ status.

….is there evidence of concomitant increase in water vapor (which causes more than 90% of the greenhouse gas effect)?…..Prof. Easterbrook.
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I thought it was established, through pollen and plant remains, that the last glaciation and Younger Dryas were much more arid than now, and the Holocene Optimum warmer and more humid.

Don’s basic approach of looking for the undeclared assumptions is the key.

Looking at the first graph here, Shakun’s fig 2, shows there is a clear and large difference between when YD is dated in the ice core and when it occurred on their new global proxy timescale.

As best as can be estimated by eye this is 1000-1500 year offset.

They assume “well mixed” CO2 hence the Vostok CO2 level is taken to be globally representative. They are using Vostok core dating for CO2 and show its small uncertainty. So they are accepting Vostok timescale and assuming their global proxy time scale is concordant with it.

This is key to their conclusion, since if you align the two timescales by identifying the YD event, there is not contention about the timing of CO2 rise , they would simply have confirmed earlier results.

So the whole premise of Shakun et al is based on the fact that YD happened about 1500 years *earlier* on a global scale than it did at Vostok. How realistic is that idea ?!

The Vostok chronology is based on d18O isotope ratios. The is determined by the *evaporation* of the water that later falls a snow. So where did this water evaporate to fall on an Antarctic supposedly still in extensive glaciation?

No, this whole anti-phase but in phase see-saw speculation is simply self-contradictory nonsense. It does not hold water (nor ice nor snow, nor even firn).

A couple of points. The proof that C02 causes warming is not from corelation. Its from experiemental evidence and basic engineering. “””””

Steve, I think you claim a little too much from the “experimental evidence and basic engineering”

Let’s start with the experimental evidence. In the real world; that being the laboratory where CO2 does its dastardly deed on our climate, the source of the energy that purports to do the heating, is (on average) a black body like source of Long wave infrared radiation having a spectral peak at about 10.1 microns wavelength, and containing about 98% of its energy in a range of about 5.0 to 80 microns wavelength, at an effective Temperature (on average) of 288 Kelvin.

That is what the LWIR emission from the earth surface looks like. I’ll leave it to you to find a peer reviewed (any peer reviewed) paper describing any laboratory observation, and measurement of heating of CO2 by such a source of LWIR radiation . (which incidently should have a total radiant emittance of about 390 W/m^2) .

Secondly, it is fairly well accepted science that CO2 can absorb LWIR radiation in the 13.5 to 16.5 micron wavelength range, which will put the CO2 molecule in a higher energy state. As to what else might get heated (if anything), there is not quite as much agreement. In particular, it is not clear that the the original source of that LWIR radiation; the earth surface (liquid and solid) is subsequently heated further as a result of the CO2 warming. Certainly, in the absence of incident sunlight, that surface will be found to be cooling, rather than heating.

But I do agree with you that the CO2 itself gets heated from such radiant energy.

So why do they not get BOTH the CO2 and TEMPERATURE estimates from the same proxy, instead of from different ones from different places around the world.

As we know from NOAA published data, CO2 is NOT well mixed in the atmosphere; in particular, the CO2 at the north pole, and at the south pole, aren’t even vaguely similar, let alone a match for each other.

I was under the impression that these expensive ice cores, gave both Temperature, and CO2 proxy information. I don’t think you can tell the Temperature in New York, by studying the geology around Melbourne, Aus.

major says: “when you read the paper and not take Willis word on the subject, you can clearly see that there are many different warming start dates for the proxy’s http://i44.tinypic.com/34gncox.jpg the paper is getting a “global” temperature record.”

Well, of course we would have more chance if getting it first hand if they did not publish behind a paywall. However, the graph you post , which it appears in Shakun’s 2b tells up quite a lot. It marks “onset of warming” 19ya BP; onset of CO2 rise 17.5ya BP.

QED.

Oddly they then twist this around to conclude the opposite. Remarkable deductive science!

I also had one question about the suggestion that Antarctic and Arctic cooling and warming were somehow “out of phase”

If such cooling or warming incidents were a result of the 26,000 year polar axis precession, would one expect exactly such an out of phase change.

Currently, northern winters occur when the earth is closest to the sun, and southern winters, when they are furthest apart. In 13,000 years or so, this condition should be reversed, so northern winters should then be more severe than southern winters.

So I believe it is to be expected that long term variations in the polar regions, should be out of phase, at least as regards, the axis wobble.

Mosh says:
>>
The paper argues this.
1. The INITIAL cause of the warming was a change in orbital parameters. THEN
2. Excess warmth in NH. Then
3. ICE melting and a fresh water pulse THEN
4. A warming in the SH, leading to
5. MORE c02 outgassed from the ocean.
C02 both leads ( enhances) and lags ( as a feedback) the temperature rise.
It doesnt really change our view of things but adds in a few more details about the sequence.
>>

Indeed it does. Which is in complete contradict with the physical evidence , it would seem.

It seems possible, someone really wanted to match proxies and ice cores, that major volcanic eruptions should leave residue in the ice and a pattern in the proxies that you could match up. Pinatubo-style eruptions seem to happen on about a 100 year basis. Proxy trees that are several hundred years old or proxy [insect (chironomids) or planktonic] sediments would have patterns that could be compared to the ice cores.

What was the method/justification Shakun used to align the proxy data and the ice core data (given that carbon dating would be inadequate)?

But just looking at the proxies – pollen, insects, sea critter species, mg/ca in sea critters – seem to have dubious relationship to temperature and anything measuring the temperature at 600m is guaranteed to be time lagged by at least a century if not more.

There are great arguments against this new paper already, thanks to Willis and Don but irrespective of any other problems:-

Aren’t the axes for CO2 and temperature deceptive? CO2 is brought up to match temperature levels, as if CO2 was responsible for all of the warming. Nobody is suggesting that, are they? Surely you need to drop the CO2 curve to match what warming you think it might be responsible for. At that point (even if you adopt some of the IPCC’s more scary values) I doubt CO2 leads temperature at any part of the graph.

At the end of the day, if increasing carbon dioxide levels preceded rising temperatures at the end of the last Ice Age, what was the mechanism which caused this to happen?

The Earth’s temperature steadily fell from ~120,000 to ~12,000 years ago and then suddenly there was an abrupt change. Leaving aside fanciful theories what could have caused the carbon dioxide levels to rise?

1. Volcanic activity – but, there is no sign of this in the geological record.

2. Sudden increase in life on Earth – that only happened after the temperature rose and our planet was able to support increased amounts of life.

3. The actions of primitive man – yeah right.

4. Er……….

The only possible answer is the oceans started to warm releasing carbon dioxide into the atmosphere.

Why did the oceans start to warm? Our sun is a variable star (all suns are variable stars) – that is one possibility – we only see short term variabilty of ~0.1% approximately 11 years, there may be a super cycle of which we are currently unaware.. The other more obvious and likely one is natural climate cycles, largely caused by variations in the Earth’s orbit.

Somewhat OT but I would like to know how well the diffusion theory is grounded and would this also apply to ammonia trapped in the ice which is regarded as a signature for an ET impact by Mike Baillie (dendrochronolgy). His graphs appear to show a clear spike with no or very little diffusion.

Very interesting is the Younger Dryas, I think that the consensus about it being a very cold spell is the strongest ever in the field of earth science, sceptics and warmers unite here.

Hence it is bound to be wrong as many geologic records -other than isotopes- do not support it.

for instance: http://www.geol.lu.se/personal/seb/Geology.pdf.pdf
“The first late-glacial lake sediments found in Greenland were analyzed with respect to
a variety of environmental variables. The analyzed sequence covers the time span between
14 400 and 10 500 calendar yr B.P., and the data imply that the conditions in southernmost
Greenland during the Younger Dryas stadial, 12 800–11 550 calendar yr B.P., were characterized
by an arid climate with cold winters and mild summers, preceded by humid
conditions with cooler summers.

“Comparisons of historic global climate warming and cooling, glacial fluctuations, changes in warm/cool mode of the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), and sun spot activity over the past century show strong correlations and provide a solid data base for future climate change projections.” [http://wattsupwiththat.com/2008/12/29/don-easterbrooks-agu-paper-on-potential-global-cooling/]

Now in this post he is stating:

“…. a most surprising conclusion in this paper is that the authors claim that correlation proves cause. Simply showing that CO2 correlates with anything surely doesn’t prove that CO2 was the cause. It’s the same kind of mindset involved with the oft-heard claim that if we have had global warming while CO2 was rising that proves the cause was the rise in CO2. Heck, I had hair before CO2 began to rise, but I don’t blame that on CO2.”

Which is it Dr Easterbrook: do strong correlations provide solid evidence or not?

Ice cores are the only proxy where CO2 and temperature are measured at the same time, from the same material. Regardless how imprecise dating of individual events is, there was period when temperature was already elevated after the last ice age and CO2 was not yet elevated. The rest 80 proxies were just temperature proxies, not CO2 proxies and they definitely weren’t measuring CO2 and temperature at the same time using the same geological layers. They may either be used to better calibrate events in ice cores, or may be interpreted as that in other parts in the world the temperature did behave differently but they don’t tell us anything about temperature-CO2 relation at that place unless we assume the CO2 concentration must be consistent worldwide while temperature doesn’t have to. But that’s not what we actually observe.

It would be nice to have the past several centuries or millenia mapped out so as comparisons can be made. Unfortunately that isn’t going to happen to everybodies satisfaction. These papers show that the same data can be used to create different histories. It may be interesting but it will solve nothing. Even the satellite record has been interpreted in different ways and we have actual readings not proxies. Why, for example, are Hansen and our Bom still using UHI effected ground thermometers when satellites give greater coverage and are not effected by UHI? We know the answer but Hansen and co are allowed indeed encouraged to continue to use flawed data. What chance Willis and Don will have their criticisms acknowledged? Zip.

major9985 says:
April 8, 2012 at 10:54 pm
, you can clearly see that there are many different warming start dates for the proxy’s http://i44.tinypic.com/34gncox.jpg the paper is getting a “global” temperature record. Is it not obvious that around the world during a major climatic shift with large areas of ice receding and forest growing over thousands of years, you are going to get a mix of proxy temperature records!!

As there are “many different warming start dates” and ” a mix of proxy temperature records” You are simply showing that there is no correlation let alone causation. Are you telling us that CO2 can choose where and when it starts the warming, if so there is nothing global about it and the whole paper is a pointless sham.

I think the main dating problem is consistency. All of the local reconstructions I am aware of indicate that CO2 lagged warming. Mcelwain et al., 2002 found that a “~77 ppm decrease in atmospheric CO2 at the onset of the Younger Dryas stadial… lagged climatic cooling by ~130 yr.” The stomata data clearly support a temperature-driven carbon cycle throughout the Holocene.

I take the approach – let’s buy into the idea and see where it takes us. Let’s assume it’s all true then logically project how the mechanism of CO2’s “ability” to bring us out of the last ice age is likely to be affecting us right now.

When you look at it that way there are a couple pesky “facts” displayed in the data that jump up and slap you in the face – WHY DID WARMING STOP? It decimates any semblance of a “tipping point”, obliterates the CAGW theory of “positive feedback” and basically shoots CAGW theory in both feet.

If CO2 going from ~180 to ~200ppm somehow launched us into rapid warming ~18K YA then WHY did temperature fall back ~13K YA when CO2 was ~230ppm and, even more perplexing, why did the rapid rate of warming cease 10K YA when CO2 reached ~260ppm if CO2 was responsible for the start of rapid warming when it was under 200ppm?

If CAGW theory was proven true as based on this paper then why aren’t the ocean’s boiling right now at almost 400ppm CO2?

Maybe instead of GHG’s bringing us to some sort of tipping point they drive climate to a FLIPPING POINT? Is it so outrageous to think that maybe our climate is BI-STABLE? Below a certain amount of GHG the climate becomes favorable to stability at ice age temperatures and above that amount it is favorable to stability at present day temperatures. If it walks like a duck…

“Because CO2 is a greenhouse gas and has been shown as the principal control knob governing the climate of the for the last half billion years.”

Not so. Firstly, nowhere does the paper you have linked ot contain the assertion that “CO2 has been shown as the principal control knob governing climate for the last half billion years.”

The paper contains all sorts of equivocations, such as “Unfortunately, no CO2 records are currently available for either of these events” – referring to the late Devonian, early Carboniferous glaciations. Then there is the anti-correlation of the late Ordovician glaciation, when CO2 levels were as high as 5000ppm, which is brushed aside with the comment “we await more data”.

The bottom line is that these proxies are attempting to determine whether CO2 leads or follows temperatures – a time resolution of only a few centuries for events that took place hundreds of millions of years ago. You see the problem.

Shakun
“…….the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age.”

“As Lemieux-Dudon point out
“One special feature of glaciological models is a large model error due to unresolved physics and errors on the forcing fields, clearly affecting the quality of the inferred dating scenarios.””

“major9985 says: “…CO2 is a greenhouse gas and has been shown as the principal control knob governing the climate of the for the last half billion years….”
False. Your reference shows association, not causation. Perhaps you misread the abstract. Perhaps you aren’t familiar with scientific principles. Or perhaps you didn’t think we’d check the link?”

The phrase “principal control knob” is the title of the paper I referenced, I did not say that CO2 was the causation of any warming. To understand the temperature of the planet, you have to take into consideration the concentration of CO2, which is what the paper I referenced explains. This has been shown over the last half billion years.

P. Solar says:
April 9, 2012 at 12:19 am

“Well, of course we would have more chance if getting it first hand if they did not publish behind a paywall. However, the graph you post , which it appears in Shakun’s 2b tells up quite a lot. It marks “onset of warming” 19ya BP; onset of CO2 rise 17.5ya BP.
QED.
Oddly they then twist this around to conclude the opposite. Remarkable deductive science!”

CO2 is not the instigator of the end or beginning of the glaciations or ice ages. It is the orbit and tilt of the earth that does it. When this earth change happens, it only melts the ice in the Northern Hemisphere which disrupts the ocean flow. This warms the Southern hemisphere. This Southern warming, releases CO2 from the ocean causing global warming. The idea is, the change in the earth’s orbit or tilt will not do as much to the planet as is observed. CO2 is the best explanation for the global warming that is seen, and this paper reaffirms the idea.

It was an increase in sun light hitting the Northern Hemisphere which caused more ice to melt. This disrupted the warm ocean flow of water from the Southern hemisphere to the Northern Hemisphere, which caused the North to cool and the South to warm up. The increased ocean warming in the Southern Hemisphere released more CO2 into the atmosphere which caused global warming. This is why CO2 is the best explanation for the ice ages. So it was a warming in the Northern Hemisphere that started this processes.

Disko Troop says:
April 9, 2012 at 2:40 am

“As there are “many different warming start dates” and ” a mix of proxy temperature records” You are simply showing that there is no correlation let alone causation. Are you telling us that CO2 can choose where and when it starts the warming, if so there is nothing global about it and the whole paper is a pointless sham.”

As the Earth warms up at present, the warming is not standard around the globe, it is different. But there is more to it when looking at the last glaciations as the paper does. The Southern Hemisphere warmed much faster than the Northern, so clearly you are going to get proxy’s showing that, which the paper explains http://i44.tinypic.com/34gncox.jpg

The proxy’s are a local temperature record, if the area that the proxy came from was covered in ice and then warmed from the increased CO2, the area would have melted over time and a forest would have grown. This area is going to show a different temperature record to an area that had no ice and a forest was there from the start. But more to the point, if you or Don J. Easterbrook has an issue with a proxy record, they are all referenced in the paper and can be researched. These proxy papers will explain why they had that type of local temperature record. This is how science works, you have to read.

Steven Mosher says:
April 8, 2012 at 10:35 pm
A couple of points. The proof that C02 causes warming is not from corelation. Its from experiemental evidence and basic engineering.

The question is how much warming.

The paper argues this.
1. The INITIAL cause of the warming was a change in orbital parameters. THEN
2. Excess warmth in NH. Then
3. ICE melting and a fresh water pulse THEN
4. A warming in the SH, leading to
5. MORE c02 outgassed from the ocean.
…

“Mosh says:
>>…
4. A warming in the SH, leading to
5. MORE c02 outgassed from the ocean.
C02 both leads ( enhances) and lags ( as a feedback) the temperature rise.
It doesnt really change our view of things but adds in a few more details about the sequence.
>>

Indeed it does. Which is in complete contradict with the physical evidence , it would seem.

4 and 5 seems to come first.”
____________________________________

The graph shows that the initial spurt of warming began c. 20 kyr in the NH (purple line, 60′-90′ N). The rise in SH only begins ‘after’ 19 kyr. The authors suggest that the initial NH warming was orbital.

This, they suggest, led to a warming N-S ocean pulse that triggered SH ocean warming c.19 kyr, releasing significant CO2. It’s only after this, post c. 17 kyr, that ‘global’ temperatures start to rise, according to the graph.

The authors suggest that the initial global warming, 20-17 kyr, was caused by orbital forcing, but that the global warming post 17 kyr was mostly due to CO2 forcing, i.e. a positive feedback response.

“The correspondence between atmospheric CO2 concentrations and globally averaged surface temperatures in the recent past suggests that this coupling may be of great antiquity. Here, I compare 490 published proxy records of CO2 spanning the Ordovician to Neogene with records of global cool events to evaluate the strength of CO2-temperature coupling over the Phanerozoic (last 542 my). For periods with sufficient CO2 coverage, all cool events are associated with CO2 levels below 1000 ppm. A CO2 threshold of below ~500 ppm is suggested for the initiation of widespread, continental glaciations, although this threshold was likely higher during the Paleozoic due to a lower solar luminosity at that time. Also, based on data from the Jurassic and Cretaceous, a CO2 threshold of below ~1000 ppm is proposed for the initiation of cool non-glacial conditions. A pervasive, tight correlation between CO2 and temperature is found both at coarse (10 my timescales) and fine resolutions up to the temporal limits of the data set (million-year timescales), indicating that CO2, operating in combination with many other factors such as solar luminosity and paleogeography, has imparted strong control over global temperatures for much of the Phanerozoic.”

Unless I am mistaken current CO2 levels are around 392 ppm. Does this mean that we are in for “widespread, continental glaciations”?

This paper, cosignated by Bard as last author, seems to be the paper too much , too much, trop trop trop for him ; it has a smell of pine tree (or coffin) as that of the « scientific » carrier of M.Mann
It looks a bit bizarre to me that it would be revolutionnary that temperatures of Northern Atlantic and tropical environments do not lag that of polar environments and ice, while the sun irradiates more the poles to the detriment of tropical latitudes ; really, as long , as they do not demonstrate that CO2 does not lag temperature in ice cores , there is nothing new ; and if they do, we are waiting for the explanations of vice président Jouzel to find the source of CO2 before the deep polar oceans started to moove

Why don’t you people (Eschenbach and Easterbrook) submit a rebutal to Nature? Obviously it is full of errors and mistakes. What you are doing now is nothing more than brabbling about a misleading paper.

Science has looked at the way CO2 participates in the climate system over the last half a billion years and comprehensive conclusions show over the long term there is indeed a correlation between CO2 and temperature, as manifested by the atmospheric greenhouse effect.” p.201. (http://earth.geology.yale.edu/~ajs/2001/Feb/qn020100182.pdf).

“The bottom line is that these proxies are attempting to determine whether CO2 leads or follows temperatures – a time resolution of only a few centuries for events that took place hundreds of millions of years ago. You see the problem.”

The paper explains its methods and the “event” took place over 10000 years, not a few centuries.

I’m still confused about the merits of temperature proxies taken from predominantly coastal locations. It appears to me that they are truly representative of neither continental nor oceanic environments.

I don’t know but it seems to me that someone is wrong here, either CO2 rose after temperature as shown in earlier ice cores, or CO2 rose before temperature as shown in these ice cores. I don’t think we can have it both ways.

Perhaps the next study will show that CO2 and temperature rose simultaneously. The we’d have all possibilities covered.

This is a very worrying situation.
The obvious questions to ask are:
Who supervised this work?
What happened to “Peer review”?
Who says these “scientists” are qualified to produce such a paper?
But this isn’t science. This is propaganda.
On the basis of the analyses so far performed, I’m not sure a part two is necessary except to demonstrate the extent to which these “scientists” ought to feel extreme shame and find a different line of work.
It is as if they started out with an objective; to show exactly what the conclusion shows, and then selected and misrepresented the data to show exactly that.
Whatever happened to analysing the data to see what the data shows?

“Unless I am mistaken current CO2 levels are around 392 ppm. Does this mean that we are in for “widespread, continental glaciations”?”

over half a billion yeas ago, the sun was 4% weaker and I think 30-40% dimmer, for the planet to be nice and warm CO2 had to be very high, 8000ppm compared to 390 today. The sun has gradual decreased over this half billion years and science has shown that the concentration of CO2 when compared to the output of the sun equals the temperature of the earth. This graph shows this correlation over the half a billion years of climate data we have http://tinyurl.com/6ppedy6

I notice that R. Gates has now taken to sniping from SkepticalScience.com rather than debating directly here. He managed to post some off-topic speculation about how the “natural negative feedback pathways become overwhelmed when [CO2 is rapidly increased]”. I mention it here only to point out that he would not get away with such rampant speculation here.

I should add that unless the authors of this paper can defend it robustly and credibly, it calls into question not just this work, but all the previous work done by the lead “scientist” Jeremy D Shakum.
It also calls into question the standards at Havard, the supervision and standards of education there and it brings into question the reputation of journals such as Nature.
The analyses on this website ought to have been performed at various stages during the preparation of this work and certainly should have been performed in any critical peer review process.
If the peer review process is so badly flawed then it is a case of “Falsus in unum, falsus in omnibus’ and taints the work of all other scientists published in Nature. Scientists who have some regard for their reputation and credibility must surely need to consider carefully the journals they submit their papers to.
It seems to me that the whole of the scientific process is seriously damaged by the Climate Change Scandal and while it is difficult to gain a reputation, it is very very easy to lose it and then it is extraordinarily difficult to recover.
It may be that some journals are terminally damaged and will eventually disappear to be replaced by new publications which impose a more rigorous set of standards and are free from the political activist traits now so prevalent.
Climate studies is a subject fast approaching the status of astrology and it too may have suffered irreparable damage. It may endure and even appear to gain in importance for a while, simply a reflection of the money poured in, but in the long term?

Thank you for raising some excellent questions. I do not feel that you should be reluctant to state, “I will confess here that I don’t believe computer models really prove anything” It should be a stated principle for scientific research that computer models, like statistics, are valuable tools to guide the researcher. Tools, such as brushes or chisels, enable artists to be creative. But scientists are not artists. A skillfull scientist can create a model that encompasses scientific principles, but the scientist can not be creative with this tool to create science. A model can only identify issues that have potential. The scientist should use the results from a model to develop a hypothesis, the first step in the scientific method. The scientist should then develop a plan to collect data that would proove or disprove the hypothesis. Using a model as the final step in the scientific process is not science, it is more comparable to playing computer games.

Bear with me here, you’ve brought a paper into discussion and actually had the audacity to read and comprehend it – how dare you!
/sarc

The existence of glaciation during +1000 ppm CO2 concentrations has always been a problem for the Ecofaschisti. As was said by another commentator, they just wave their hands “waiting for more data.”

This all is a massive attempt to rewrite geological history. Historical revisionism has widely been practiced by those who aim to totally control the poletariat/serfs. Now they’re trying to use another form of fear to drive it. It’s not working out so well, and so we see a doubling down on revisions. It’s so interesting to watch. You don’t need to believe in c*racy to see that like puppies wiggling around the alpha male, newly minted scientists are inclined to support their professors and subsequently those who were taught garbage, promptly generate more. I’m strongly in favor of ridding the ecosystem of that particular type of garbage!

Nothing wrong with being a “Lukewarmer”. I strongly believe a warmer earth with abundant CO2 for the biosphere is a win-win situation.

However, the CAGWCF (CF for “Control Freaks”) is another matter entirely–they’d have you believe we must erase 100 years of industrialization from carbon-based fuels and be forced into wind and solar solutions that have no overall economic advantage–they seem to see a cliff that nobody else sees. Oh, and they’ll control your light switch along with just about everything else.

a second problem results from possible diffusion along the walls of an air bubble, which can upset the CO2 concentration in the bubble.

The diffusion was studied along the remelt layers in the Siple Dome ice core, a “warm” core (-23°C). See:http://catalogue.nla.gov.au/Record/3773250
While that is not necessarely the same as for “normal” ice layers, the results give a broadening of the resolution from 20 to 22 years for middle depths (at a few kyr back) to 40 years for the deepest layers (70 kyr back). Hardly a problem. For the much colder (-40°C) Vostok and Dome C ice cores, there is far less migration, as even the thiniest waterlayer at the edge of the ice crystals is gone at -32°C. Moreover, if there was any migration at all, the ratio between CO2 level and temperature (proxy) would fade over time, for each interglacial/glacial 100 kyr further back in time over 420 and 800 kyr. Which is not observed.

Thus, while the exact timing of the average CO2 age is a real problem, CO2 diffusion is not a problem in the “cold” ice cores.

I have noted this same problem in all papers with the seemingly purposeful exclusion of error bars in reconstructions of ice core and other proxy CO2 and temperature graphs, regardless of which is leading and which is lagging. Both sides overstate the case in my opinion. It was this observation that led me to agree with Nick that it appears that there is data to be had that may show CO2 increase precedes temperature increase. Leading versus lagging CO2 is a fair and questionable focus of research endeavors.

Given the spread of proxies, it would not be hard to find data that appears, at first glance, to agree with one’s pet theory fairly easily. The above reviewed paper has done that. But this is where Nick and I part company. On second glance, and with proper attention to error bars, which the authors failed to do, at the very least it should give us pause to consider that neither side has a lock on this.

There are three basic statements to make when reporting findings. The two gold standard classics are yes, there appears to be a statistical difference, or no there appears not to be a statistical difference. The post modern era AGW scientists seem willing to submit papers that have not completed this essential statistical step and appear very willing to convince us of their eye-ball opinions. Worse, Hansen appears eager to pick the pockets of all based on such a conclusion.

It diffuses from areas of high concentration to low concentration. SO high concentration bubbles will diffuse toward the outside, to be in equilibrium ONLY when the concentration in the bubble is equal to concentration outside.

A small problem here: we measure 180-300 ppmv CO2 in the ancient air bubbles, but our present outside air is already near 400 ppmv. Thus if there was any migration, we would see an increasing gradient between older air and current air, but over the full length of the ice core, not only over the past 160 years… And the ratio between CO2 level and temperature (proxy) for the older parts would be different than for the younger parts. In addition, 180 ppmv is already critical for several plant species, thus a substantial migration would mean that the real values were even below 180 ppmv…

ALSO, when the ice core is removed from “down under”, where there exists high pressure at the bottom of the ice column, the pressure is removed, and the ice bubbles, retaining the pressure from below, diffuse faster toward lower pressure at the surface. Diffusion then becomes directly proportionally increased in accordance with the pressure gradient. This is additive to the diffusion gradient.

That implements that the migration speed for CO2 is faster than for O2/N2, or there wouldn’t be a change (I do expect the opposite, as CO2 has a higher affinity to the ice surface than O2 or N2). The deep cores are kept on low temperature for almost a year to expand the ice (“relaxation”). Once the internal and external pressure would be the same, any migration would go from out to in. And again, that would give different results for the deeper parts than for the younger ones.

Specific to this study, it does not such thing. It flies in the face of conventional thought which the lukewarmers embrace. But, to the ‘how much’ question, I reckon it would be analogous to trying to warm your house with a laser pen with the windows open. (Unique CO2 absorption spectrum)

Towards this study, though, if the CO2 increased first, and assuming it was well distributed, how is it the Antarctic was lagging behind the rest of the world? If that’s true, it destroys much current climate thought. ….. And then there’s the question of how the CO2 spontaneously emerged to cause any warming.

To me, this is a great victory for the hard skeptic line. It can’t really be both, this paper being science or current climate thought.

Major9985,
“The paper explains its methods and the “event” took place over 10000 years, not a few centuries.”

In that case, there is no possible way to discern whether CO2 preceded the temperature changes or lagged them. And no one has explained the anti-correlation of the late Ordovician glaciation – a piece of evidence for falsification if ever there was.

suyts says:
April 9, 2012 at 7:11 am
….. And then there’s the question of how the CO2 spontaneously emerged to cause any warming.
========================================
They left three things out….
They don’t say what their starting CO2 levels actually were, you have to get that from their graphs….that would be the first clue
They don’t consider how unstable the extremes are, either high or low, and they purposely picked an extreme for a starting point

..and most important, they left out the biology…
…and what happens when something becomes limiting

As long as there is an overlap between increasing or decreasing temperature and CO2 levels, it is (near) impossible to determine which drives what to what extent.

Surely, increased temperatures causes more CO2 to escape from the oceans. Surely more CO2 will have some effect on temperature. The problem is how much.

The first is calculated as about 8 ppmv/°C in the Vostok and Dome C ice cores. That are ice cores in deep inland Antarctica at high altitude. The snow/firn/ice comes from precipitation reflecting the evaporation of about the whole SH oceans. There is an indirect measurement of NH temperatures by d18O in N2O, which reflects mainly the NH ice sheet buildup.
There is hardly any difference between CO2 in the NH or the SH, if averaged over a year, thus the ice core smoothing over 560-600 years for the long term ice cores gives the global CO2 average over the glacial/interglacial periods.

Now we have a period where the decline in temperature and CO2 don’t overlap, even if the timing of the CO2 lag may have some error: that is the end of the previous interglacial, the Eemian.
Temperature and CH4 levels were already at a minimum and ice sheet building already at a new maximum before CO2 levels started to drop. The subsequent drop of 40 ppmv CO2 had no discernable influence on temperature or ice sheet buildup. As CH4 and CO2 both are measured in the gas phase, the timing problem doesn’t play a role here. See:http://www.ferdinand-engelbeen.be/klimaat/eemian.html

I agree with Mike M (4/9, 2:59 am) that the most significant fact is being overlooked here. Why did the warming stop?

The Caillon et al study, Indermuhle et al, and others show prretty well that temp change preceeds CO2 change – whether increasing or decreasing. But time uncertainties are large and I still have major reservations that a gas bubble in ice is a representative sample of paleoatmosphere.

Nonetheless, the ice-core records show a characteristic saw-tooth pattern through 4 major glacial cycles – long-term cooling trends, rapid warming, and then onset of another prolonged cooling trend.

Cooling begins at the peak (both temp and CO2) of the interglacial period

Warming begins at the nadir (both temp and CO2) of the glacial period

CO2 simply cannot be driving temperature because, when the trend reverses, CO2’s purported forcing effect is going in exactly the wrong direction for the subsequent change.

–
P. Solar (April 9, 2012 at 12:27 am) wrote:“This seems to be another case of publish your results but spin AGW into the abstract to ensure publication and next years grant and so the media can continue to misinform the public.”

They say power has to be secured & maintained in order to be exercised. We live in a capitalist system. The math’s simple. Alarmists have secured and maintained financial power while nonalarmists cheaply take advantage of the free labor of severely overworked volunteers. The alarmists are very well-funded to work comfortably (in private) on natural variability because they have restrained themselves sufficiently administratively & politically to reach beyond the level of screaming protester. And (if they want to) they can read here to get free ideas on natural variability. That’s dominance, a quality found throughout nature. If there’s investment in nonalarmism, it’s going to the wrong people – i.e. people who aren’t qualified to supervise good volunteers. Classic example of the Peter Principle all the way around.

gnomish says:
April 8, 2012 at 8:55 pm (Edit)
maybe the co2 came out of the cold polar waters when it warmed rather than from the warmer equatorial ones that were already depleted?
once a soda is flat, it can’t fizz any more.

—————————————————————

But we are told that the warmer oceans, having been warmed by CO2, were now absorbing the extra CO2 so as to become less alkaline. ( There is no explanation as to why the ocean giving up CO2 shouldn’t become more alkaline ).

Perhaps I am being a little slow but it looks to me as though either CO2 warms the oceans causing them to give up further CO2 or the extra atmospheric CO2 being predicated is absorbed by the ocean which in the process becomes less alkaline. You really can’t have both.

FerdiEgb states that “even the thiniest waterlayer at the edge of the ice crystals is gone at -32°C.” The paper, “Reconstruction of past atmospheric CO2 concentrations by ice core analysis”, acknowledges that, due to impurities, liquid water can exist as low as -50 deg C. Diffusion of CO2 into this water, due to its far higher solubility than nitrogen and oxygen, will partially deplete the CO2 from trapped air bubbles. If the liquid water subsequently freezes, the excess CO2 will appear as very tiny trapped bubbles, far smaller than the size of the ice grains resulting from crushing the ice sample during the analysis process. Most of the CO2 in the tiny bubbles will not be released during the crushing process and the analysis will underestimate the CO2 content of the past atmosphere. Call it the “Don Ho” effect.

Spencer Weart, in his book “The discovery of Global Warming” mentions it took two decades to develop reliable methods of giving plausible results when analyzing ice cores and states “The trick was to clean an ice sample scrupulously, crush it in a vacuum, and quickly measure what came out”. I suppose “Quickly” gave the “Plausible” results they wanted to see.

The putative evidence that the present CO2 levels are higher than has ever been in the last 800,000 years is what convinced people that CO2 was something to worry about.

1. As others have mentioned, is the error in the YD time due to mixing two different time scales? It looks like the 1950 year difference between BP and BC/AD.

2. What wasn’t addressed in Shakun were the errors in dating the proxies. The large spread among the proxies implies a lot of error in dating.

Dr. Easterbrook mentions the error in dating the ice core proxies. As far as determining whether or not CO2 preceded or lagged temperature, ice core temperature vs. CO2 is self consistent whether or not the dates are wrong. That result is a lot more robust than comparing ice core CO2 to temperatures elsewhere.

3. As I asked in Willis’ thread, aren’t the O18 levels in the ice cores a measure of global temperature? What purpose is served by measuring local proxies without associated CO2 levels?

In Figure 2 is the CO2 PPM supposed to represent atmospheric CO2? I may be reading things incorrectly, but it would seem to me that greenhouse gases must be in the atmosphere, as opposed to buried under ice and snow, to be part of the greenhouse effect.

With a measure of 190 PPM for all of LGM and part of OD, would that not have been too low to sustain life?

Most of the CO2 in the tiny bubbles will not be released during the crushing process and the analysis will underestimate the CO2 content of the past atmosphere. Call it the “Don Ho” effect.

The method used to determine the isotopic ratios in ice core gases is by sublimating all ice under vacuum over a cryogenic trap and subsequent sublimating all ingredients step by step. That avoids any isotopic separation and traps almost alll CO2, wherever it might be hidden. This method gives the same overall CO2 level as the cold crushing method, but more accurate isotopic measurements.
See for more information, including the methods:http://courses.washington.edu/proxies/GHG.pdf

Imputities are a main problem in Greenland ice cores where a mix of seasalt/carbonate and acidic dust from Icelandic volcanoes can produce CO2 in situ, but is less of interest in deep inland Antarctic ice cores, except during the deepest times of glacials, when far more dust is deposited. But even so, most of the hidden CO2 is recovered, as the measurements are either at sufficient vacuum to evaporate all surface water and elevated temperature (below freezing) by crushing or all ice is sublimated.

But indeed it did take a lot of time to make the methods as accurate as possible…

In Figure 2 is the CO2 PPM supposed to represent atmospheric CO2? I may be reading things incorrectly, but it would seem to me that greenhouse gases must be in the atmosphere, as opposed to buried under ice and snow, to be part of the greenhouse effect.

What is buried in the ice cores is only a tiny fraction of what resides in the atmosphere, but it represents near the same composition as in the atmosphere, be it averaged over 8-600 years, depending of the accumulation rate.

With a measure of 190 PPM for all of LGM and part of OD, would that not have been too low to sustain life?

Fortunately, at least for a part of the day, CO2 levels near the surface over land are average a lot higher than in the bulk of the atmosphere. While CO2 levels in the ice cores reflect the average (95%) of most of the atmosphere, CO2 near ground (5%) may be 40-50 ppmv higher.

But we are told that the warmer oceans, having been warmed by CO2, were now absorbing the extra CO2 so as to become less alkaline. ( There is no explanation as to why the ocean giving up CO2 shouldn’t become more alkaline ).

In ancient times, CO2 was following temperature: indeed if seawater warms, it releases CO2 and becomes more alkaline. But that is limited: 1°C increase for the global ocean surface gives ~16 ppmv extra in the atmosphere when everything is again in dynamic equilibrium. But vegetation works in opposite way: warmer means less ice and more land occupied by plants, thus more sequestering of CO2. The global change as found in ice cores is ~8 ppmv/°C. Now humans have added a lot of extra CO2 above the temperature increase since the last ice age, or even since the Little Ice Age. We are now about 100 ppmv above what the ice cores say as the “normal” CO2 level for the current temperature. That means that some of that extra CO2 now is pushed into the oceans (and vegetation, causing more growth) and makes the seawater less alkaline…

DRG54 says: This, they suggest, led to a warming N-S ocean pulse that triggered SH ocean warming c.19 kyr, releasing significant CO2. It’s only after this, post c. 17 kyr, that ‘global’ temperatures start to rise, according to the graph.

Yeah right, so let’s recap. NH started warming -20ya, which … pulse…blah … warmed SH about -19ya, and ONLY AFTER this did “global” temperatures rise.

So at -19ya when SH is same and NH is hotter the world is globally warmer but it’s not global warming. (See you have to be clever to do climate ;) )

AT -18ya both SH and NH are both already warmer but NH is cooling , so the Earth is already warmer globally but it’s not because of global warming.

At -17.5 ya, SH is well up and ramping higher; NH is cooler by about half what SH is warmer, so the world is already warmer but it’s not because of global warming.

Then the fact that the world is globally warmer after a couple of thousand years of NON global global warming going on the NON global warming has caused some CO2 out-gassing. This in turn causes one of them thar’ tippin points and woah !!

FerdiEgb says:
April 9, 2012 at 8:44 am
“But indeed it did take a lot of time to make the methods as accurate as possible”

It has been my experience as a metrologist many years ago, that researchers often mistake good repeatability for good accuracy. Has anyone taken recently deposited firn, mechanically compressed it to form ice, aged it for a while, then analyzed the ice using the present ice core analysis techniques to see if the results agree with the present atmosphere?

In reply to my question you say, “What is buried in the ice cores is only a tiny fraction of what resides in the atmosphere”. That seems to confirm that the Figure 2 is intended to represent atmospheric CO2. The chart ends with CO2 levels at 260PPM, which also had me confused as CO2 levels are reported to be near 400 PPM…but you answer that next “CO2 levels near the surface over land are average a lot higher than in the bulk of the atmosphere. While CO2 levels in the ice cores reflect the average (95%) of most of the atmosphere, CO2 near ground (5%) may be 40-50 ppmv higher.”

The cart end with levels of 260PPM, far more than 40-50ppm below modern CO2 surface levels. Why would that be?

Also, wouldn’t a graph of the raw data of CO2 trapped in the ice core produce the same graphic? Why massage the data?

Also, the rise in CO2 seems to proceed temp rise by hundreds of years (figure 2), but we are currently supposed to be experiencing CO2 rise with near immediate consequences. Should we be looking for a reason for modern warming in some long past rise in CO2?

I found the answer to one of my questions…I mistakenly thought that Figure 2 ended in the modern age, but it actually ends in 4000BC….why leave out the most recent 6000 years?
———————————————————————————————

FerdiEgb says:
April 9, 2012 at 9:19 am
But vegetation works in opposite way: warmer means less ice and more land occupied by plants, thus more sequestering of CO2
=================
So, even though we are running a huge biological filter….things like bacteria, yeast, fungus etc have nothing to do with it
That’s nice to know……….

Since Co2 is now driving temps….anyone have any idea why it took temps over a thousand years to catch up? CO2 jumped up….but temps didn’t get the memo for a long time (blue line)

JustaMom says:
April 9, 2012 at 9:47 am
Also, the rise in CO2 seems to proceed temp rise by hundreds of years (figure 2), but we are currently supposed to be experiencing CO2 rise with near immediate consequences.
==========================
bingo…

Let’s start at the beginning. The sun melted large quantities of ice …. Hmmmmm, that would significantly reduce the albedo of the planet. That should lead to warming of the planet. Oh, the planet warmed. What a surprise.

Occam’s razor … the simplest solution …

All the rest is just a shade above pure nonsense and I’m not at all surprised Mosher, along with all the alarmists, wants to believe it. Confirmation bias in action.

BTW Mosher, can you show us the experiment conducted in a 20 mile column of air that “proves” CO2 warms the planet. You assert it exists, please provide a reference.

Richard M says:
April 9, 2012 at 10:46 am
…
All the rest is just a shade above pure nonsense and I’m not at all surprised Mosher, along with all the alarmists, wants to believe it. Confirmation bias in action.

BTW Mosher, can you show us the experiment conducted in a 20 mile column of air that “proves” CO2 warms the planet. You assert it exists, please provide a reference.

The 12 easy steps to understanding physics of the minor, but important, GHG effect.

1. The ‘motion’ of Electrons and Protons can be affected by externally applied electric and magnetic fields. Computer CRTs are an example with the electron beam forced towards the phosphor-coated screen by more or less ‘static’ electric field all the while under the back and forth influence of a dynamic magnetic field from the deflection coils (called ‘the yoke’ in the trade).

2. Conversely, when Electrons or Protons move, they create ‘fields’ and then perhaps (propagated) ‘waves’ as well. Electromagnets and antennas are examples.

3. Molecules, such as CO2 and H20 are comprised of atoms the components of which are Protons and Electrons (we ignore the Neutron). This is elementary; consult any HS text for a refresh.

4. Many molecules such as O2 (and even CO2 and H2O) have specific mechanical resonances, at specific frequencies (or wavelengths if one prefers).

5. These mechanical resonances are like miniature tuning forks. The vibrational modes get a little intricate and differ from molecule to molecule on account of the ‘atomic relationship’ of the member atoms.

6. During these vibrational modes, certain ‘member’ atoms can move more than others, and some ‘parts’ are electrically charged … referring to 2. above this will create a ‘field’.

7. Should a particular frequency EM field pass by a resonant molecule, the molecule, like a resonant dipole antenna will ‘pick up’ (the field will induce into the molecule) energy from the passing field .. refer to 1. above.

8. The actual resonant frequencies of resonant molecules is affected by pressure; this means more collisions between atoms, and sometimes vibrational energy can be absorbed in a collision while sometimes energy is given off. ‘Broadening of spectral lines’ is the basic effect.

9. Any vibrational modes amount to ‘stored energy’,

10. Said ‘stored’ energy is also continually being re-radiated (refer to 2. above) in basically all directions (any given molecule will have a given radiation pattern, but in the aggregate among all randomly oriented molecules this yields an ‘omni’ directional pattern).

12. From insolation (incoming sunlight), to heating of the earth’s surface, some convective heating of the air near the surface (consult a meteorology text; the MAJORITY of the heating of the air is in the boundary layer), to radiation of LWIR from the earth’s surface, some LWIR is captured’ (excites or is EM induced into) various GHG molecules e.g. CO2 and H2O … and that ‘captured’ EM energy is re-radiated in all directions, *including, and this is very important: BACK to earth … some term this ‘back radiation’, perhaps after the close radio term, ‘back-scatter’ (as used in RADAR to identify energy ‘reflected’ or scattered back from a target).

And so there you have it.

The 12 easy steps to understanding the minor but important (as to moderating the surface temperature) GHG effect.

It has been my experience as a metrologist many years ago, that researchers often mistake good repeatability for good accuracy. Has anyone taken recently deposited firn, mechanically compressed it to form ice, aged it for a while, then analyzed the ice using the present ice core analysis techniques to see if the results agree with the present atmosphere?

Even better, there is an overlap of about 20 years between the high accumulation ice cores at Law Dome and the direct atmospheric measurements at the South Pole:
Etheridge e.a. measured CO2 in firn top down to closing depth and in ice. There was no difference in CO2 levels between still open pores, measured in sampled air and already closed pores, measured in the normal way of ice crushing.

James Sexton, thank you for pointing to the answer to my question, “I mistakenly thought that Figure 2 ended in the modern age, but it actually ends in 4000BC….why leave out the most recent 6000 years?”

Thank you all for your help. I appreciate being responded to with respect while I try to wrap my mind around all this science.

Thanks to all of you who take the time to respond to the non-scientists who are trying to educate themselves. Even when I’m not the one asking the questions, I read through the comment section of every post I read and learn from you.

>The paper argues this.
1. The INITIAL cause of the warming was a change in orbital parameters. THEN
2. Excess warmth in NH. Then
3. ICE melting and a fresh water pulse THEN
4. A warming in the SH, leading to
5. MORE c02 outgassed from the ocean.
C02 both leads ( enhances) and lags ( as a feedback) the temperature rise.
+++++++++++++

Let’s reasonably assume the oceans during the ice age were CO2 balanced with the atmosphere. Melting ice has a tiny amount of CO2 in it. Nearly none. Melting ice makes water that will immediately absorb CO2. Lots. If it did not (which is against basic physics but suppose it did not) it would drop the CO2 level in the oceans by dilution – the oceans and it would not outgas, or not outgas nearly so much, even when warmed. Either way the CO2 is reduced in the atmosphere unless significantly compensated.

Question 1: How much CO2 goes into the atmosphere when there is a small temperature rise in the ocean – enough heat to melt the ice?
Question 2: How much CO2 does the meltwater absorb?
Question 3: Which is greater?

I ask because the paper has a freshwater pulse (taking CO2 out of the air) and later CO2 outgassing from the (diluted) ocean. But that outgassing would only replace, or partially replace, the draw down. Remember we are talking about several hundred feet of ocean rise. The CO2 needed to balance that new water to 300 ppm is many thousands of GTons – more than is in the atmosphere at present.

The claim is that ‘once the melting started…’ the CO2 was immediately released. This is simply not going to happen. Once the melting started it immediately took CO2 from the atmosphere, 300 g/m^3. The ocean volume increase comes from the thousands of cubic miles of new (initially) CO2-free water.

Perhaps it draws it down but the CO2 outgassing from warming oceans eventually starts to catch up – after 800 years.

“There was no difference in CO2 levels between still open pores, measured in sampled air and already closed pores, measured in the normal way of ice crushing.”

I guess I failed to make my point. I was wondering if the combination of increased pressure and aging has been proven not to affect the CO2 content of the trapped air bubbles by somehow hiding CO2. The reference you provided didn’t answer that question as the samples were not deep enough in the ice/firn to have been exposed to the presssures of typical ice core samples.. Athough your reference in a previous post showing the sublimation process that can be used was helpful. Is the CO2 analysis data from various ice cores such as Vostok using the sublimation technique available?

Jim, I understand the GHE. Too bad you stopped at 12. You needed to go further because there’s more to the physics of GHGs in the atmosphere.

Energy in the atmosphere doesn’t just sit there. It gets radiated to space. What molecules accomplish that? Well, it’s those very same GHGs. So, when these GHGs are energized through normal kinetic collisions they will radiate in all directions. Some of that radiation heads out to space. So, just like the GHE keeps some energy that was heading to space within the planet’s surface-atmosphere, the cooling effect takes energy within that system that was going nowhere and radiates some of it to space.

Do you know how this balances? I don’t, but I suspect it varies by concentration of the GHGs and the global temperature. I suspect the GHE is dominant at low concentrations of GHGs. However, as the concentration increases the effect starts to saturate. At some point the cooling effect may even become stronger the warming effect.

The bottom line is I have never seen these two opposite effects handled anywhere. When Mosher and you claim that the GHE is proven by physics that is all fine. But, that doesn’t mean GHGs net effect is that of warming. You need to look at the big picture which is why I made the comment about an experiment on a 20 mile column of air.

In ancient times, CO2 was following temperature: indeed if seawater warms, it releases CO2 and becomes more alkaline. But that is limited: 1°C increase for the global ocean surface gives ~16 ppmv extra in the atmosphere when everything is again in dynamic equilibrium.

++++++++++

Hang on a minute! If the oceans rise 50 feet, how many million cubic miles of water is that? We have ice melting to water with no CO2, absorbing 300 ppm by the time it is seawater, and you are saying that the release of CO2 is only a miserable 16 ppm per degree?? How many tens of degrees did the ocean temperature supposedly rise?

How on earth does this outgassing lead to a net increase in the atmosphere when the ice is still melting? The argument in the paper is that ‘once the heating gets started, the CO2 outgassing drives the melting’. That just don’t add up!

If the CO2 magically rose 100 ppm, and then melted a few million cubic miles of ice, that would become sea water and absorb 300 ppm (-ish). There is a heck> of a lot more new ocean water than there is new CO2 in the atmosphere. It is plan bad arithmetic to say that outgassing 16 ppm per degree, even for the whole ocean, can feed an uptake of 300 ppm for the new seawater when the rise was what, 400 ft?? Come on!

The paper treats the ice as if it already contains the same amount of CO2 as the ocean which is patently not the case, then attempts to tinker with the timing of the ‘releases’ to have that precede melting. Thanks for the 16 ppm number. A simple BOE calculation shows several orders of magnitude of impossibility. The paper’s proposed mechanism is bunk.

Richard M says April 9, 2012 at 12:20 pm
…
Jim, I understand the GHE. Too bad you stopped at 12. You needed to go further because there’s more to the physics of GHGs in the atmosphere.

Energy in the atmosphere doesn’t just sit there. It gets radiated …

Please, elaborate (I see that you may have tried), but, you also skimmed right over an important part I wrote, and which I’ve bolded below:

12. From insolation (incoming sunlight), to heating of the earth’s surface, some convective heating of the air near the surface (consult a meteorology text; the MAJORITY of the heating of the air is in the boundary layer), to radiation of LWIR from the earth’s surface, some LWIR is captured’ (excites or is EM induced into) various GHG molecules e.g. CO2 and H2O … and that ‘captured’ EM energy is re-radiated in all directions, *including, and this is very important: BACK to earth … some term this ‘back radiation’, perhaps after the close radio term, ‘back-scatter’ (as used in RADAR to identify energy ‘reflected’ or scattered back from a target).

So, in a word: “covered”. (How elaborate do you think one gets in a “12 easy step” elavator speech anyway?)

It might help you if you had a few concepds in mind too when considering this subject, like ‘space’ is the big energy ‘sink’ with old sol (and the internal heat generating processes (including nuclear) of the earth) as sources … any mechanism that results in a delay of energy leaving earth, such as a ‘bounce-back’ or a re-rad of energy (like back radiation) certainly is going to increase the ‘energy flux’ in the system, and this in any way you want to frame the argument translates to a ‘higher’ energy state, and a higher so-called temperature” (movement in matter, velocity of air molecules or oscillations in certain ‘resonant molecules) as well.

This really is a pretty ‘basic’ system to set up, but, owing to size, owing to energy affecting phase ‘state’ phase changes (e.g. liquid to vapor etc), owing to physical transport to area other than where it was initially ‘radiated’ (insolation) onto the earth get to be problematic in actually modeling.

Now, with your initial complaint being to Mosher in the form of:

BTW Mosher, can you show us the experiment conducted in a 20 mile column of air that “proves” CO2 warms the planet. You assert it exists, please provide a reference.

I’d like to see how you would support the proposal on how ‘physics’ would work with a GHG to make the surface of the earth cooler.

Do the oceans outgas and absorb at the same rate when temperatures rise and fall in equal measure?

As an example, in a real world situation if 5000 sq miles of ocean at our sort of latitude, warmed by 10 degree centigrade during one summer, fell back the same amount in the winter, then rose again by 12 degress centigrade the next summer and fell back the same amount in the winter and so on, over a ten year period, would the co2 outgassing and absorption be exactly the same?
Tonyb

Please, elaborate (I see that you may have tried), but, you also skimmed right over an important part I wrote, and which I’ve bolded below: “and that ‘captured’ EM energy is re-radiated in all directions”.

Nope, you didn’t get it. Is this concept really that hard to understand. There’s no question that the energy gets radiated randomly in all directions. That is not the issue. There is no question that the surface radiates LWIR. That is not the issue. You have to quit assuming I’m talking about these issues.

I’m talking about energy in the atmosphere. It may have got there in any number of ways. From the sun, from conduction, from latent heat, from thermalization of LWIR. It doesn’t matter. It’s now in the atmosphere.

Now what happens to that energy? That is what I was trying to get across. It gets radiated, but consider that the energy is already in the surface-atmosphere system. If it gets radiated to the surface it still exists within that system. It hasn’t changed the overall energy content of the system. But, if it gets radiated to space it is no longer within surface-atmosphere system. Hence, it constitutes a cooling effect on the overall system.

Or, to use your own words slightly modified:

“any mechanism that results in a quicker path for energy leaving earth, such as a outward radiation, certainly is going to decrease the ‘energy flux’ in the system, and this in any way you want to frame the argument translates to a ‘lower’ energy state, and a lower so-called temperature.”

.deadwood05 says:
All this is akin to measuring mass differences of micrograms with a spring scale and using the average of several thousand measurements out to four decimal places.

Indeed, but when you do a further several thousand measurements, will they give the same four digits? For independent random errors with the same mean (i.e., no drift), the accuracy increases with the square root of the number of measurements. Thus ten thousand measurements will get you two decimal places. Four places requires a million measurements, but how do you know they’re drift free? By doing another million and getting the same answer!

“For independent random errors with the same mean (i.e., no drift), the accuracy increases with the square root of the number of measurements. ”

I think it does not increase the accuracy, it establishes a mean value with greater and greater confidence. The accuracy (and the standard deviation about the mean) remain an unvarying feature of the measurement system.

Std error in the mean = Stdev/Sqrt(N) where N is the number of readings

_Jim says:…
The 12 easy steps to understanding the minor but important (as to moderating the surface temperature) GHG effect. Refutations with cite(s) of applicable physics law(s)/principle(s) appreciated.

Will you refute that incoming solar IR to the top of the atmosphere is as similarly affected by GHG but in the opposite direction? Where’s that in the IR balance of climate models?

major9985 says:
April 9, 2012 at 3:52 am Thank you for your response to my post.
However ot seems to me that the scenario you are describing does not need any input from CO2. You describe changes in the Earth’s albedo at various places which no doubt will increase the warming from the initial solar or orbital event. Where is the need to add CO2 to this well recognised process of a change in albedo.
My second thought is why do we chase the mouse around the house when there is an elephant in the room. The change in water vapour content will reinforce the warming from orbital change until cloud increases and sets in the negative feedback. If it was CO2 doing it there would be an endless positive feedback and we would all be toast.
Why do we chase the CO2 mouse when water vapour is well known to be the main greenhouse gas, the Earth is 70% ocean..plenty of it. It strikes me, as this is the simplest explanation as science requires, that we can ignore the minor influence of a small increase in CO2 caused by outgassing.

“Where is the need to add CO2 to this well recognised process of a change in albedo.”

CO2 is causing the global warming and in turn the glaciers to melt. This increase in albedo would affect the temperature proxy records in the regions which lost ice. New tree growth would also have an effect on the regional proxy records. The orbit/tilt warming is only seen in the far northern hemisphere. Shakun et al paper shows that when you added up all the warming that took place, 93% of it was due to CO2.

“If it was CO2 doing it there would be an endless positive feedback and we would all be toast.”

Steven Mosher says:
April 8, 2012 at 10:35 pm
A couple of points. The proof that C02 causes warming is not from corelation. Its from experiemental evidence and basic engineering.

The question is how much warming.

The paper argues this.
1. The INITIAL cause of the warming was a change in orbital parameters. THEN
2. Excess warmth in NH. Then
3. ICE melting and a fresh water pulse THEN

So the ice melted before the CO2 increased
I picked this up surfing the internt:
“Glaciation
For a number of reasons, the volume of glacial ice near the poles
waxes and wanes over time. As a result, water is alternately taken from or added
to the world oceans. This can result in sea-level oscillations of up to 200
meters. For example, modern continental glaciers are 1.5 to 2.5 km thick and have
a total estimated volume of 33 million km3. If we assume the maximum volume
of Pleistocene glaciers to have been 71.3 million km3, Flint, 1971 then
the difference is 38 million km3. Using the assumption that glacial water
volume is 91.7% of the volume of sea water from which it is derived, a sea-level
drop of 106 m can be accounted for by Pleistocene glaciation. Melting of the
present Greenland and Antarctic glaciers would produce a sea-level rise of
approximately 60 meters.

The specific latent heat of fusion of ice at 0 ºC, for example, is 334
kJ.kg-1 This means that to convert 1 kg of ice at 0 ºC to 1 kg of water at 0
ºC, 334 kJ of heat must be absorbed by the ice. Conversely, when 1 kg of water at
0 ºC freezes to give 1 kg of ice at 0 ºC, 334 kJ of heat will be released
to the surroundings. (Note for educators).

“The total mean mass of the atmosphere is 5.1480×1018 kg with an
annual range due to water vapor of 1.2 or 1.5×1015 kg depending on
whether surface pressure or water vapor data are used; somewhat
smaller than the previous estimate. The mean mass of water vapor is
estimated as 1.27×1016 kg and the dry air mass as 5.1352

A 4C rise or higher this century would see the world warm almost as
much in 100 years as it did during the 15,000 years since the end of
the last ice age.”

So about 1000 times as much heat went into melting the glaciers at
the end of the Pleistocene as went into heating the atmosphere,
implying CO2 had only a negligible effect- A. McIntire

It seems to me that the heat first went into the atmosphere (regardless of its source) and then the glaciers melted. Hard to believe the mere release of CO2 into the atmosphere could propagate such melting. How much CO2 would that take? Shouldn’t we be able to take a known quantity of ice, seal it in a vessel, and then introduce CO2 and watch it melt? Isn’t that what we’re told? That CO2 warms the atmosphere?

Hang on a minute! If the oceans rise 50 feet, how many million cubic miles of water is that? We have ice melting to water with no CO2, absorbing 300 ppm by the time it is seawater, and you are saying that the release of CO2 is only a miserable 16 ppm per degree?? How many tens of degrees did the ocean temperature supposedly rise?

The equilibrium between CO2 in the oceans and in the atmosphere is a matter of pressure, not a matter of quantity. Even when a ~100 ppmv increase in the atmosphere increases the partial pressure of CO2 (pCO2) of the upper part of the oceans with ~100 microatm, the total amount in the atmosphere increases with 30%, but in the ocean surface layer (the “mixed layer”) with only 3% (that is called the Revelle factor, ~10). That is because in the oceans, an increase of CO2 uptake reduces the pH, and that has a tremendous influence on the equilibrium reactions which then goes back from carbonate to bicarbonate to free CO2. Thus the 210 GtC extra CO2 in the atmosphere is in equilibrium with ~30 GtC extra CO2+bi+carbonate (total Dissolved Inorganic Carbon – DIC) in the upper ocean layers (there is about 800 GtC in the atmosphere and 1000 GtC in the oceans mixed layer). Fresh water can absorb even less CO2, as that has no buffer factor at all and any CO2 in solution will cause a sharp drop in pH and thus push it back into the atmosphere.

Further the volume in the oceans is not of interest for the pressures involved: It does hardly make a difference if you shake a 0.5, 1.0 or 1.5 liter bottle of coke: at the same temperature, the same pressure will be reached in the air above the coke, as long as there is sufficient CO2 moving from the coke to the air above.

The above also is true for the opposite effect: if there were no other fast releases (like lots of volcanoes spewing lots of CO2 in short time), the ocean temperature will give more or less CO2, until a new dynamic equilibrium between ocean releases (mainly near the tropics) and sinks (mainly near the poles) and the biosphere releases and sinks is reached.

Thus the extra CO2 comes from the oceans, not from the ice and may or may not have helped to melt the ice (which I doubt)… But anyway there is little influence of the ice volume on the CO2 levels in the atmosphere, either direction.

Do the oceans outgas and absorb at the same rate when temperatures rise and fall in equal measure?

Hello Tony,

Theoretically it should be and it looks like that way, as an increase (1998 El Niño) or decrease (1992 Pinatubo) in temperature has about the same effect in opposite direction, and the ~1°C wobble in temperature over the seasons (due to the difference in land area between the NH and SH) also shows a similar effect. Both give 4-5 ppmv/°C change, from seasonal to decadal, but that is all around the trend which is going up. The ice cores show ~8 ppmv/°C in both directions, be it with long lags: ~50 years for the MWP-LIA cooling, ~800 years for the glacial-interglacial transition and several thousands of years for the interglacial-glacial transition.

I guess I failed to make my point. I was wondering if the combination of increased pressure and aging has been proven not to affect the CO2 content of the trapped air bubbles by somehow hiding CO2. The reference you provided didn’t answer that question as the samples were not deep enough in the ice/firn to have been exposed to the presssures of typical ice core samples.

At some depth, most CO2 and deeper also N2 and O2 will be compressed in such a way that clathrates are formed and no visible bubbles remain. After substracting these deep ice core parts, they are allowed to relax for at least a year, so that most clathrates are decomposed and the bubbles are reformed. Still remaining clathrates decompose – even violently – under vacuum as used at measurement time, but remaining non-destructed clathrates may hide some of the CO2. This may influence the results.

I guess I failed to make my point. I was wondering if the combination of increased pressure and aging has been proven not to affect the CO2 content of the trapped air bubbles by somehow hiding CO2.

The main problem in deep ice cores is the formation of clathrates, where CO2 (and N2 or O2) can hide, even if crushed under vacuum. That seems to give the largest error. The sublimation technique has no problem with that, but it is quite recent and I don’t know in how far that was used in the most recent ice cores.

Since oxidation reactions are reversible, it appears to me that the sublimation chamber, being illuminated with infrared lamps, could provide the energy needed for endothermic chemical reactions, and could hide CO2 by producing hydrocarbons from CO2 and water. After all, plants to this by photosynthesis, and they will grow when illuminated with red vsible light. Just a thought.

Somewhat OT but I would like to know how well the diffusion theory is grounded and would this also apply to ammonia trapped in the ice which is regarded as a signature for an ET impact by Mike Baillie (dendrochronolgy). His graphs appear to show a clear spike with no or very little diffusion.
_____________________________________________________
Different chemistry

ABSTRACT
By applying the inverse relation between numbers of leaf stomata and atmospheric CO2 concentration, stomatal frequency analysis of fossil birch leaves from lake deposits in Denmark reveals a century-scale CO2 change during the prominent Holocene cooling event that occurred in the North Atlantic region between 8,400 and 8,100 years B.P. In contrast to conventional CO2 reconstructions based on ice cores from Antarctica, quantification of the stomatal frequency signal corroborates a distinctive temperature–CO2 correlation. Results indicate a global CO2 decline of Ϸ25 ppm by volume over Ϸ300 years. This reduction is in harmony with observed and modeled lowering of North Atlantic sea-surface temperatures associated with a short-term weakening of thermohaline circulation. http://www.pnas.org/content/99/19/12011.full.pdf

Two sacred cows of CAGW are:
1. CO2 is well mixed in the atmosphere.
2. CO2 data from Ice Cores is correct because it shows CO2 levels prior to industrialization were low.

Anyone who tries to refute either of these basics of CAGW is subject to attack.
Historic CO2 measurements 1826 to 1960: http://www.biomind.de/realCO2/

Even if you have not the slightest knowledge of ice cores, what Jaworowski says can’t be true on two main points: One can’t find lower levels in ice when the outside CO2 is much higher. CO2 migrates from high to low levels if cracks are present, not the other way out. The presence of high CO2 levels when drilling fluid in cracks are detected proves that .
And the “arbitrary” shift of ice core CO2 data “to match the Mauna Loa data” only proves that he doesn’t (want to) understand that the age of the gas composition is (a lot) younger than the age of the ice at closing depth, because of migration of CO2/air from the atmosphere through the still open pores. Quite remarkable for an ice core specialist.

Most of his objections of 1992 where already rejected in 1996 by the work of Etheridge e.a. on the three Law Dome ice cores, but until his death, he still insisted on his objections.

As said before: ice core data are real, directly measurable CO2 data averaged over 8-600 years, depending of the local snow accumulation rate. Stomata data are local CO2 proxies, subject to local changes in growth, precipitation, fertilisation and land use changes, including traffic and industrialisation, in the main wind direction. As they grow over land, the average CO2 level is already 40-50 ppmv higher than in the bulk of the atmosphere. That bias is taken into account by calibrating the stomata data against… ice cores over the past century.
The averaging in ice cores doesn’t change the average of the CO2 levels found. If stomata data show a higher or lower average over the same period of time, then the bias in the stomata data did change over time.

Thus your reference of CO2 levels during the Younger Dryas only shows that the local/regional landscape (vegetation type and growth speed) changed due to the harsh conditions of that period. Nothing global.

Thus please don’t use Jaworowski or Beck or stomata data as “proof” that the ice core data must be wrong, you make all skeptics unbelievable on points where the “consensus” is far less solid: the real effect of 2xCO2.

BTW, if satellites don’t show more difference than +/- 8 ppmv CO2 in the mid-atmosphere in all parts of the globe, while over the seasons some 20% of all atmospheric CO2 goes in and out, then I call that “well mixed”…

You make reference to the fine deconstruction of the paper by Willis E. in a previous WUWT thread. In the light of that – and especially with reference to your point 2 – I think it worthwhile to draw attention to a point I made in that thread. I copy it here to avoid the need for you and others having to find it.

Richard

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richardscourtney says:

April 12, 2012 at 4:35 pm

Willis:

Thankyou for yet another of your superb critiques of a paper.

I write to support two comments you have made in the subsequent thread.

At April 6, 2012 at 6:01 pm you say;

“What I’m seeing from these proxies is that we don’t know as much as I thought we did about the shape and timing of the emergence from the last ice age. The other proxies tell a very different story from the ice cores …”
And at April 6, 2012 at 7:28 pm you say;
“Whatever ‘something’ these proxies are measuring, it’s clear that they are not measuring the same something. For example, the GRIP greenland ice cores show warming, starting 27,000 years ago. They warm slowly for about 10,000 years, then they warm rapidly to a peak about 10,000 years ago, and after that, they gradually cool down.”

Yes! Oh, yes!

I have repeatedly pointed out (in several places including WUWT) that
(1) ice core data are useful because they indicate CO2 concentration and isotope-derived temperature data from the same trapped gas bubbles
but
(2) ice core data are NOT a direct indication of anything because
(2a) different ice cores provide different indications
and
(2b) other proxies (e.g. stomata data) provide different indications to those of the ice cores and to each other.

The entire AGW edifice is built on dubious data. Therefore, much that is asserted as being “known” (e.g. temperatures and their changes, atmospheric CO2 concentrations and their changes, etc.) is very, very debateable. Please note that this applies to both proxy-derived data of the distant past and to measurement-derived data averaged to provide global and hemispheric information of the recent past.

With the possible exception of the satellite-derived data, all of the basic climate parameters are of unknown accuracy, reliability and precision. And this problem becomes obvious whenever different data sets for the same parameter are compared.